Process for regulating setting time of hydraulic cement

ABSTRACT

The present invention is an improved one of the U.S. Pat. Application Ser. No. 211,307 now U.S. Pat. No. 3,782,992 and relates to a process for regulating setting time of hydraulic cement which comprises clinker containing 5 - 60 % by weight of 11CaO.7Al2O3.CaX2, more than 5 % by weight of 3CaO. SiO2, and further 2CaO.SiO2 solid solution and 4CaO.Al2O3.Fe2O3; anhydrite with or without hemihydrate; at least one selected from the group consisting of sugars, sodium hydrogen carbonate, water-soluble phosphates, carboxylic acids, silicofluorides, sodium silicates, ligninsulfonate, sulfuric esters of higher alcohol and alkylsulfonates, whereby the anhydrite is contained in an amount that Al2O3/SO3 weight ratio of Al2O3 in the clinker and SO3 in the anhydrite is 0.7 - 1.8 and hemihydrate is contained less than 5 % by weight based on SO3.

106-89. AU 115 EX 2-4-75 OR 3.864.138 United States Patent 1191 11113,864,138

Uchikawa et al. Feb. 4, 1975 1 PROCESS FOR REGULATING SETTING TIMEOF'HYDRAULIC CEMENT Primary Examiner-Delbert E. Gantz AssistantExaminerJames W. Hellwege [75] Inventors g izz thgg fi z g z ig g ofAttorney, Agent, or Firm-Oblon, Fisher, Spivak,

McClelland & Maier Japan [73] Assignee: Onoda Cement Company, Limited,

Onoda-shi, Yamaguchi, Japan [22] Filed: May 15, 1972 [57] ABSTRACT Thepresent invention is an improved one of the US.

[21] Appl' 253352 Pat. Application Ser. NO. 211,307 now us. P31. N0.

3,782,992 and relates to a process for regulating set- [30] ForeignApplication Priority Data ting time of hydraulic cement which comprisesclinker May 22, 1971 Japan 46-34979 Containing 5 60 y weight of 1 i2 nn,

. more than 5 by weight of 3CaO, S10 and further [52] U.S. c1. 106/89,106/315 2Ca0-Si02 solid solution. and z 6- 2 3; n- [51] int. Cl C04b7/02 hydrite with or without hemihydrate; at least one [58] Field 61Search 106/104, 109, 92, 1 10, lected from the g p nsi ing of sugars,sodium y- ,/3 4, 315 89 drogen carbonate, watwmhnwes, carboxylic acids,silicot'lu0rides, sodium silicates, ligninsul- [5 References Cit dfonate, sulfuric esters of higher alcohol and alkylsul- UNITED STATESPATENTS fonates, whereby the anhydrite is contained in an amount that AlO /SO weight ratio of A1203 in the 3,147,129 9/1964 Armstrong et al....:g 1 g? g' 3' x and g 3,188,221 6/1965 Matsuda eta]. 106/315 Y rateScomame 0 Y base 3,628,973 12/1971 Greening 106/89 SO3- 3,666,515 5/1972Nakagawa 106/104 FOREIGN PATENTS OR APPLICATIONS 1,029,501 5/1966 GreatBritain 106/90 3,087,825 4/1963 Meier-Grolman 7 Claims, 4 DrawingFigures FIG.I

Compressive Strength of Cemenfl Added Amount of Golactose(xl0"%)FATENIED W5 I 3.864.138

sum 20F 4 FIG.2

Difference between Initial and Fmal Sethng T|me(m|n) Added Amount ofGulactoseh IO 0T5 |.'o L's 2 .0

Added Arnomt of Galactose(xl0"%) PATENTED FEB SHEEI 3 OF 4 FIG.3

QE ZBStm 3850 A3203 in CI inker/ 50 m Anhydrite PAIENIEI] FEB 4 i975Compressive Strength SHEET 4 OF 4 XALY x y '50! |oo- Added Amount of N02SiF 7 (based on F) PROCESS FOR REGULATING SETTING TIME OF HYDRAULICCEMENT The present invention relates to a process for suitablyregulating setting time of hydraulic cement which has high strength atthe initial and later stages. The initial and later stages means lessthan 6 hrs and more than 3 days, respectively, in the present invention.

When the mixed raw materials comprising calcareous, silicious andaluminous material as well as a small amount of halide such as calciumfluoride. calcium chloride, etc. are sintered, the initialcrystallization region of calcium aluminate (3CaO.Al,O,-,) is extremelynarrowed and the clinker obtained will not contain calcium aluminate,and contains 1 lCaO. 7Al,0;,.CaX, (X represents a halogen atom) as astable phase, and thus the clinker containing 1 lCaO.7Al O .CaX, as astable phase. as well as 3CaO.SiO=, 2CaO.SiO 4CaO.Al O Fe,0,, etc. isobtained.

llCaO.7Al- O .CaX, component has a high hydration activity and a greaterhardenability, so it is effective that hemihydrate (or hemihydrategypsum) is added to the clinker containing 1lCaO.7Al O;,.CaX,

component for retarding the setting time thereof and also insolubleanhydrite (or insoluble anhydrite gypsum) is added to the clinkercontaining llCaO.7Al- ;.CaX, for developing strength in the initial andthe later stages. However, as disclosed by the U.S. Pat. ApplicationSer. No. 21 1,307, now U.S. Pat. No. 3,782,992 we have found that if atleast one of sulfates. nitrates and chlorides of potassium, sodium,magnesium, calcium, aluminium and ammonium (excepting CaSO .l/2H O), isadded to the clinker as a substitute of hemihydrate, setting time ofcement thus obtained is retarded and the hardened matter has excellentstrength, and that if the above-mentioned additive is added to theclinker with anhydrite and hemihydrate, setting time of cement thusobtained is retarded and the cement have good workability and moreexcellent strength development property at the early and the laterstages than that of the former cement. The early stage means between 6hrs and 3 days in the present invention.

An object of the present invention is to provide a process forregulating setting time of hydraulic cement comprising l1CaO.7Al- O .CaXby-using an additive other than the above-mentioned additives.

Another object of the present invention is to provide a process forpreparing cement which has good workability and high initial strengthand a hardened material thereof has high strength for a long period oftime.

We found that in addition to the above-mentioned additive, sodiumhydrogen carbonate, water-soluble phosphates, silicofluorides, sodiumsilicates, sugars, carboxylic acids, ligninsulfonates, sulfuric estersof higher alcohol or alkylsulfonates is effective.

The present invention can be more fully understood from the followingdetailed description when taken in conjunction with reference to theaccompanying drawings, in which:

FIG. 1 shows the relation between the compressive strength of cementmortar comprising the clinker and the added amount of galactose whenanhydrite is added or is not added.

' FIG. 2 shows the relation between a difference between the initial andthe final setting time or the setting time of the cement mortar as usedin FIG. 1 and the added amount of galactose.

FIG. 3 shows the relation between the compressive strength of cementmortar comprising the clinker and Al O /SO ratio of A1 0 in the clinkerand SO; in anhydrite.

FIG. 4 shows the relation between the compressive strength of cementmortar comprising the clinker and the added amount of sodiumsilicofluoride (based on F).

Bauxite, quick lime, and copper slag as well as fluorite were ground,respectively, and mixed so as to obtain clinker having a composition asshown in Table l. The resulting mixture was shaped and sintered at1,320" 1,330C. The thus obtained clinker was ground to powder havingBlaine specific surface area of 3.700 cm /g. The composition of theclinker analized by X-ray diffraction analysis are shown in Table I.

Table 1 Mineral com position (7!) Natural gypsum having a composition ofTable 2 was used to produce the following products.

Hemihydrate: The natural gypsum of Table 2 was kept at C for 3 hours andwas cooled and ground to powder having a Blaine specific surface areaof5,000 cm lg.

Insoluble anhydrite: The natural gypsum of Table 2 was kept at 800C inan electric furnace for 1 hour, and was cooled and ground to powderhaving a Blaine speciflc surface area of 4,200 cm /g.

These gypsum products were used after the chemical form thereof wasidentified by thermal analysis such as diffrential thermal analysis orthermobalance analysis.

In order to determine the relation between the amount of galactose to beused and the setting time or the compressive strength after setting ofcement mortar, the setting time and the compressive strength of mortarwere determined with respect to cement in which galactose was mixedalone'and in which anhydrite was mixed in combination with galactose inan amount that Al O /SO ratio of A1 0, in the clinker and SO, inanhydrite is 1.2 by weight.

The initial and final setting time of mortar are determined inaccordance with the test method for setting of paste described in .IIS R5201, using a sample of which the cement/standard sand (yielded inTOYOURA) ratio is 1:2 by weight, and water/cement ratio is 0.55 byweight and the strength of mortar is determined in accordance with thetest method described in .115 R 5201.

The results are shown in FIG. 1 and FIG. 2. In these figures. numerals land 2 show the cases which anhydrite is not added and is added.respectively.

It has been found from these results that when galactose is used alone,the setting time of mortar is retarded and the compressive strength ofmortar in the initial stage increase with increase of the amount ofgalactose,

anhydrite and 271 by weight of hemihydrate are added to the clinkershown in Table l and the abovementioned additives are added to the thusobtained cement.

but when galactose is added more than a fixed amount, 5 AS has beenobserved the above w hgmiinu thie compressivesltreiggth in the initialSIZgQESAO Z drate is added to the clinker the initial and later ncontrast wit t e a ove-men ione 1 as een l stren th of the thus obtainedcement increase. found that when anhydrite is used in combination with 5relation bemeeh the Setting time or the galactose although h Settingtime is retarfjed F pressive strength, and amount of used additives wasthan when galactose is used alone, strengths in the inistudied withrespect to chhkcrs containing 5 60% of tial and later stage developremarkably. This facts tell IlC307Ahowcax2 and more than 5% of 3Ca05iO-ythat existence ofanhydrite and galactose is essential for and furtherz'caosiozq WHO/U203 etc. and th'3 3 122 8 2: igt ggi z ig uzz gs iz g ig g ggl sults were similar as the results obtained by the abovementionedexperiments. sett'n time o rau ic cement w ic com rises rides, sodiumsilicates, ligninsulphonates. higher alco- 'ii g 5 60% b weight of llCaO.7Al-

yof l 2 'O. 'l -lt' d 4CZ10-Aln0. The relation between the compressivestrength of i gs $1 g f f g ifg f z at i addcd l 7% y weight based F andanhydriw dium hydrogen carbonate. water-soluble phosphates, added atvarious Anon/s03 weight ratio of Al O in the (e g orthro P K E f f h g?t clinker and SO in anhydrite to the above-mentioned phmes) cdrboxyhc fli a ac] k The :esuhs are Shown in FIG 3 etc), silicofluorides. sodiumsilicates, ligninsulfonates,

2 12 beesneobserved in the above it is prefep sulfuric esters of higheralcohol and alkylsulfonates, able to add insoluble anhydrite to theclinker in an whereby the l 'l comanled m amount that amount that theratio of A1 0 in the clinker and S0 {AMOS/SO wel.ghI.ranO of A1203 m the.clmker "F I 0 '7 in the anhydrite is 0.7 l .8 and hemihydrate iscongnutjhela gnhydrite, that is, A 0 /5 3 ratio is between 0 tamed lessthan 5% by ht based on 3- It has been found also that when an additiveother In the present mvenuoni the above'mem'oned than sodiumsilicofluoride is used, a similar result as the mes Should b usedpreferably m F amount of above-mentioned is obtained as shown by theaddition 7 by wel'ght for monosacchandei 9- by weight for disaccharide.0.05 1.00% by wei ht for of sodium silicofluoride. F l I g The relationbetween the compressive strength of polysacchandaO-l by wellghtforSodlum hydro mortar and the added amount of sodium silicofluoride genCarbonate; omwelgm based on P205 for was studied with respect to cementin which various luble phosphates (Orthophosphatesi P P amounts ofsodium silicofluoride are added to the mix- Phales and pQ yp p l l 50% yWeight ture of 13 by weight of anhydrite and 2 by weight 40 based on F rslllcofluorides (Mew -r of hemihydrate. These results are shown in FIG.4. 2 y g IUm silicates; 0.03 3-07! y AS has been observed in the aboveHG, 4 the weight for sulfuric acid esters of higher alcohol andalpressive strength of the mortar increase gradually withkylsulfonaltesi y w gh for y fw increase of the added amount of sodiumsilicofluoride -gtartaric acld ol'vdlscarboxyllc acids, 8' adlplc anddecreases gradually after addition of a fixed Kid amount of sodiumsilicofluoride. The added amount lower than one shown in the It has beenfound also that the initial and later above is not effective for thesetting time and the comstrength of mortar increase with addition ofhemihypressive strength of mortar or concrete and the added drate to themixture of anhydrite and sodium silicofluoamount more than one shown inthe above extremely ride as compared FIG. 3 with FIG. 4. retards thesetting time and lowers and strength at the Table 3 shows the relationbetween the setting time later stage as well as at the initial stage.and the compressive strength of mortar when 15% by As has been explainedabove, existence of anhydrite weight of anhydrite or a mixture of 13% byweight of in clinker is responsible for the initial and later high Table3 Setting time Amount of addition of mortar tmin.) Compressive strengthof mortar (kg/cm) Clinker Anhydrite Hemihydrate Additive lnitial Final 3hrs. 6 hrs. l day 3 days 7 days 28 days 13 2 C 17 25 112 l96 295 340 436ane sugar 85 15 C 03 14 23 .80 124 197 310 363 445 am: sugar 85 13 2 d2.: d 20 2x l37 148 256 2148 375 513 O lLllTI l y rogen x5 15ghosgihalcpgo3 I9 24 122 135 212 286 346 446 use on 85 13 2 Ad do. U 24311 133 I56 240 310 357 475 ipic act 1 15 15 0.2 l4 I8 127 241i 290 343450 its 13 2 do. 23 30 W2 I62 263 325 3x4 476 5 strength development ofcement. Addition of anhydrite with hemihydrate in clinker is effectivefor increasing the initial and later strength. The added amount ofhemihydrate is preferable to be 0.1 5.0% by weight based on S for cementand the added amount of anhydrite is most preferable to be 0.7 1.8 at AlO /SO weight ratio of the amount of A1 0 in the clinker and the amountof S0 in the anhydrite and hemihydrate in the cement. When Al O -,/SOratio is lower than 0.7, the hardened material of mortar or concrete iscracked and broken down and when Al O /SO ratio is more than 1.8, thecompressive strength of mortar or concrete decreases remarkably.

According to the present invention, the setting time of mortar which isprepared from the clinker comprising 5 60% by weight of llCaO.7Al Ocax,. more than 5% by weight of 3CaO.Si()- 2CaO.SiO- 4CaO- .Al O .Fe Oetc. is not only regulated within a range of from 7 to 40 minutes, butalso the mortar or concrete provides good workability and the hardenedma- EXAMPLE White clay, white bauxite, quicklime. copper slag and asmall amount of gypsum as well as calcium fluoride,

calcium chloride were grounded by a shaft ball mill, 85 cm in diameterand 100 cm in length, and were mixed by means of a large-sized mixer soas to obtain clinker having a composition as shown in Table 4 and theresultant mixture was shaped by a rotating roll, 60 cm in diameter. Theshaped material is sintered by a small-sized rotary kiln so that freelime in the obtained clinker was lower than 0.5% by weight. Theseresults are shown in Table 4.

The obtained clinker was mixed with gypsum listed in Table 5, calciumligninsulfonate, calcium alkylsulfonate and sulfuric ester of higheralcohol, sodium hydrogen carbonate, sodium tripolyphosphate, magnesiumsilicofluoride, respectively, at the ratio listed by Table 6 and eachthus prepared cement was tested for the setting time and compressivestrength of mortar in accordance with the test method 115 R 5,201. Theresults are summerized in Table 6. In Table 6, the setting time and thecompressive strength of mortar prepared from cement which was mixedalone gypsum to the above clinker were listed to compare with the aboveresults.

What is claimed is:

1. A process for regulating the setting time of a hy' draulic cement,which consists essentially of: admixing the retarders anhydrite and asilicofluoride with a clin- Table 4 Kind of Chemical composition (9%)Free Mineral composition (76) clinker SiO, A1 0 Fe O CaO MgO SO, Na o K0 Total lime C A .CaX, C 5

A 15.9 15.7 2.3 61.9 0.5 1.2 0.08 0.07 97.6 0.2 X=F 51 27 B 17.8 15.12.0 61.5 0.4 1.0 0.03 0.05 97.9 011 X=Cl 44 Note: Mineral compositionwas determined by means of X-ray diffraction analysis.

Table 5 Kind of gypsum ig.loss SiO, Al,O +Fe,O CaO MgO 50;; TotalHemihydrate 6.1 1.8 0.9 37.5 0.2 53.6 100.1 Anhydrite 1.9 1.0 40.0 0.357.2 100.4

Ta hlc 6 Setting time of Amount of addition (71 by weight) mortar (min.)Compressive strength of mortar (kg/cm) Clink- Anhy- Hemi- Additivelnitial Final 3 hrs. 6 hrs. 1 day 3 days 7 days 28 days er drite hydrateSurface active agent A comprising mainly l 18 127 204 308 354 495 85calcium lignin- 17 22 (25.4) (29.8) (40.4) (65.4) (70.7) (89.9)

sulfonate 0.3"

A Sodium hydrogen 108 136 239 288 318 466 85 15 carbonate 0.8 25 (24.4)(30.1) (49.5) (53.3) (68.2) (89.7) A Sodium tripolyl 10 126 250 289 345453 85 15 phosphate 0.5 19 26 (25.3) (27.4) (55.6) (57.9) (72.4) (87.1)A Magnesium silico- 136 166 262 310 357 491 84 I2 2 fluoride 2.0 (based25 30 (31.6) (36.5) (55.6) (60.0) (73.1) (90.6)

on F) Surface active agent A comprising mainly 130 154 246 276 343 48415 sulfuric ester 23 30 (30.5) (33.6) (52.3) (57.4) (71.5) (90.4)

of higher alcohol 0.3 B Magnesium silico- 224 275 324 478 84 14 fluoride2.0 26 34 (25.4) (30.4) (49.9) (56.8) (62.5) (826) Surface active agentA comprising mainly 124 230 g 293 326 476 85 15 calcium alkyl- 15 25(27.6) (34.2) (50.9) (59.6) (69.5) (88.1)

sult'onate 0.3

Note: 1) Values in parentheses show bending strength (kg/cm) kercontaining 5-607 by weight of llCaO.7 M CaX wherein X represents ahalogen atom, and more than by weight of3 CaO.SiO solid solution. 2CaO.-SiO solid solution and 4 CaO.Al O .Fe O wherein the anhydrite is presentin an amount such that the weight ratio of A1 0 in the clinker to so inthe anhydrite is 0.7 to L8.

2. The process of claim 1, wherein the cement further containshemihydrate.

3. The process of claim 2, wherein said hemihydrate is present in saidcement in amounts less than 5% by weight.

4. The process of claim 1, wherein said cement contains OJ-5.0% byweight of a silicofluoride based on the fluorine content of saidsilicofluoride.

5. A hydraulic cement composition consisting essentially of a clinkercontaining 5-60% by weight of llCaO.7Al O .CaX wherein X represents ahalogen atom, and more than 5% by weight of SCaOSiO solid solution.ZCaQSiO solid solution and 4CaO.Al- O Fe O anhydrite; and asilicofluoride, wherein the anhydrite is present in an amount such thatthe weight ratio of Alo in the clinker to S0 in the anhydrite is O.7l.8.

6. The hydraulic cement composition of claim 5. wherein the cementcomposition further contains hemihydrate,

7. The hydraulic cement composition of claim 6. wherein the cementcomposition contains less than 5% by weight hemihydrate.

2. The process of claim 1, wherein the cement further contains hemihydrate.
 3. The process of claim 2, wherein said hemihydrate is present in said cement in amounts less than 5% by weight.
 4. The process of claim 1, wherein said cement contains 0.1-5.0% by weight of a silicofluoride based on the fluorine content of said silicofluoride.
 5. A hydraulic cement composition consisting essentially of a clinker containing 5-60% by weight of 11CaO.7Al2O3.CaX2, wherein X represents a halogen atom, and more than 5% by weight of 3CaO.SiO2 solid solution, 2CaO.SiO2 solid solution and 4CaO.Al2O3.Fe2O3; anhydrite; and a silicofluoride, wherein the anhydrite is present in an amount such that the weight ratio of Al2O3 in the clinker to SO3 in the anhydrite is 0.7-1.8.
 6. The hydraulic cement composition of claim 5, wherein the cement composition further contains hemihydrate.
 7. The hydraulic cement composition of claim 6, wherein the cement composition contains less than 5% by weight hemihydrate. 